BlackBerry nerds will most likely agree with me here - great enjoyment comes from installing new BlackBerry OS builds, and finding improvements (and as with any beta build, bugs) over the old version(s).  It doesn't matter if it's 15 improvements or 5; it's the thrill of the ride.  That being said, OS 4.7.0.42 was leaked for the BlackBerry Tour 9630, and though the changes aren't yet known, I echo other BlackBerry users when I say I hope it fixes the HTML e-mail text issue.

Some are claiming that, after the update, their trackball troubles (scrolling from left to right, usually) have been resolved.  If you remember back to the launch of the Tour, the first device I purchased suffered from the aforementioned trackball issue.  Once I exchanged it for a second one, I was ready to go.  The issue has sparked a great deal of debate as to whether the issue is hardware or software related.  On one hand, exchanging the device worked for me - but on the other hand, reports have flooded the internet about users who have trackballs that work fine in one application, and not in another.

So, if you're comfortable, go for it!  OS 4.7.0.42 can be found here - but be sure to download at your own risk.

Source: CrackBerry